Rheological implications of post-seismic deformation following the 2019 Ridgecrest Earthquakes

Camilla Penney, & Jean-Philippe Avouac

Published August 12, 2019, SCEC Contribution #9454, 2019 SCEC Annual Meeting Poster #239

Large earthquakes provide an opportunity to probe the rheology of the lithosphere and upper asthenosphere. The 2019 Ridgecrest earthquakes occurred in an area which may have significantly heterogeneous rheological properties, due to its proximity to the Coso volcanic field. This volcanic field, which is located to the NW of the Mw7.1 rupture trace, is a region of high heat flow and geothermal activity.  The locally high temperatures in the Coso volcanic field are likely to be associated with low viscosities compared to the surrounding regions, and high pore pressures due to the hydrothermal activity.  The aftershock sequence associated with the Ridgecrest earthquakes shows a notable absence of large magnitude earthquakes in this region. We present models of the possible afterslip and viscoelastic response driven by coseismic stress changes in the July 2019 Ridgecrest earthquakes  and investigate in particular the possible effect of the Coso volcanic field. By modelling a series of different afterslip geometries, shear-zone frictional properties and viscoelastic rheologies we aim to identify features of the GPS and InSAR time series which might be diagnostic of different post-seismic deformation mechanisms and rheological heterogeneities.

Citation
Penney, C., & Avouac, J. (2019, 08). Rheological implications of post-seismic deformation following the 2019 Ridgecrest Earthquakes. Poster Presentation at 2019 SCEC Annual Meeting.

Related Projects & Working Groups
Ridgecrest Earthquakes